Butterfly Bush 'Black Knight'

Price : $4.97

Type: Perennial but most people think of them as shrubs

Light: Full sun

Bloom season: Summer

This heavy bloomer is rated best of the species by the Arnold Arboretum. Its dark purple flowers are the most deeply colored of all the varieties. Easy to grow. Likes well drained soil and is relatively drought tolerant. Blooms tend to be larger and more prolific on its new growth so mulch in fall and prune back to the ground in late winter. Attracts butterflies and hummingbirds.